Drill press for tapping attachment



Feb. 6, 1940.

H. G. PROCUNIER DRILL PRESS FOR TAPPING ATTACHMENT Filed Jan. 23, 1959 Patented Feb. 6, 1940 UNITE STATES era FFiCE 5 Claims.

An object of this invention is to provide a drill press for tapping attachment which may be operable by a member which is positively driven in both directions but which drives through con necticns which are yieldable in either direction if the tap or other tool employed is stuck or forcibly held or is prevented from entering the Work for any reason thereby preventing breakage of the tool orassociated parts.

An other object is the provision of means for readily and separately adjusting the force exerted by the yieldable means for-forcing the tap into the work and for withdrawing it therefrom.

Still another object is the simplification of these adjusting means and their location with respect to the work so that an operator can readily adjust the pressure to be applied to a shaft carrying the tapping attachment either in feeding or withdrawing the tap without moving from the position he normally occupies at the machine.

These and other objects as will hereinafter appear are accomplished by this invention which is fully described in the following specification and shown in the accompanying drawing in which:

Figure l with tapping attachment tion;

Fig. Zis, an enlarged vertical section on the line 2-2 of Fig. 1; and

Fig. 3'is an enlarged transverse section on the line 33 of Fig. 2. i

This is an improvement on my application for Drill press for tapping attachment, Serial No. 130,325, filed March 11,1937, since issued as Patent No. 2,160,674, May 30, 1939.

The embodiment illustrated comprises a drill press having a base H) from which rises a tubular standard H on which is mounted a bracket i2 is a perspective view of a drill press embodying the invenwhich carries a motor H3 at one side while in the other side is suitably journaled a shaft I 4, the.

The means-for raising and (01. 10-139) 7 loweringthe shaft M together with the tapping attachment it ,and tap 20 form the basis for the present invention and will now be described in detail. A slide 22 is slidably guided in guide ways 23, 2d and carries an arm 25 which is aperably secured to the shaft M so that the shaft and theslide move up and down together.

The slide 22 is hoilow and internally threaded to receive the upper threaded end of a compression adjusting rod 26 which is adjustably screwed therein after which it is locked in place by means of a lock nut 2'1. The lower end of this compression rod is threaded and has an adjusting nut, 28 screwed thereon. This nut carries a screw 29 which extends outwardly from the nut and serves for rotating the same withrespect to the rod 26 as 'will presently be explained.

Above the nut 26 and serving as an upper stop is secured at its upper end to a ring 33 which is slidably fitted over the compression rod. The upper. end of the sleeve is riveted over the ring. This sleeve has a vertically extending slot 34 which serves as a guide for the screw 29.

At the lower end of the rod 26 is an intermediate sleeve lifihaving an enlarged unrolled portion 36 with. upper and lower reduced cylin 'drical portions; On the upper cylindrical portion which a retaining ring 38 is placed thereover and the .two riveted or otherwise secured in place with sufficient looseness, however; to permit the ferrule to be readily rotated on the intermediate sleeve. Upon assembling, however, the ferrule is held while the sleeve 32 is firmly secured in place thereon after which thetwo normally rotate togather to efiect the rotation of the nut 28 on the compression adjusting rod 25.

The lower end of the-intermediate sleeve 351's a duplicate of that described and has rotatably mounted thereon a ferrule 39 which is retained in placeby means of a ring 40. The ferrule 39 is similarlyreoluced and screw-threaded to receive the upper screw-threaded end of a lower adjust ing sleeve 4!. The lower end of this sleeve has a ring d2 secured therein as by riveting and this ring is rotatable on a tension adjusting rod 43 which has a collar 44 secured thereon by means of a tapered pin 45. This collar acts as the lower limit for the sleeve 4! and the collar 44 acts to transmit an upward thrust of the rod 23 to the sleeves above as will soon be apparent. The lower end of the rod 43 is screw-threaded to be screwed into 'the upper end of a power rod 46 and is locked thereto by means of a nut 31. This power rod may be a piston rod operating in an air cylinder 48 and may be driven up and down by 'means of air fed to the cylinder through pipes 49. The mechanism for operating such a power mechanism is quite complicated particularly where it is set to drive the rod 46 up and down at a predetermined rate which may be adjusted. This mechanism, however, forms no part of the present invention and therefore is not shown in detail.

The tension adjusting rod d3 likewise carries a nut which has an adjusting screw 5i which extends through a slot 52 in the lower adjusting sleeve M. A compression spring 53 is placed between the nut 58 and the ring '32. ikewise, a compression spring 54 constantly exerts pressure between the nut 23 and the ring 38 within the upper adjusting sleeve.

It will be apparent from the foregoing that as the power rod 46 is lowered, pressure is exerted through the nut 55! upon the compression spring 53 thereby placing the sleeves 4t, 35 and 32 in tension. The sleeve 32 is firmly secured to the ring 33 and this bears directly upon the collar 30, thence through the rod 26, through the slide 5''; 22 and arm'25 to the shaft i l and ultimately to the tap 293. It will be observed that in this operation the only yieldable member is the compression spring 53 and that the stiffness of this spring will depend upon the setting of the nut at. If, therefore, the tap in being lowered misses the hole, which it is intended to screw-thread, and instead strikes a solid portion of the work, the spring 53 will yield and no damage will be done.

In backing the tapout of the work, it sometimeshappens that the tap will become clogged with chips and will stick in the work. When this occurs, pressure is exerted by the power rod upon the sleeves 35 and ll thereby causing the rod 26 to be forced into the sleeve 32 compressing the spring 56. This again insures against any damage being done due to forcing the tap at a time when it is stuck in backing it out.

The adjusting sleeves are so placed as to be readily accessible to an operator who either stands or sits infront of the tapping machine. With a little practice he will readily understand that a little more pressure or a little less is required to properly drive the tap into the work and he can accordingly adjust the sleeve ti to give the necessary pressure. Also he will soon learn just how much adjustment is required of the upper adjusting sleeve 32 to give the best result in backing the tap out of the work. In either of these adjusting operations it is usually sufllcient for him to take hold of the necessary adjusting sleeve and to turn it without holding the other sleeve. However, should it be desirable to hold the other sleeve, this can readily be done by hand or by adding a bracket to the intermediate sleeve enlargement 36 which bracket will engage any stationary part of the drill press such as the standard ll.

Thus it will be seen that a very simplified and efficient form of drill press is provided with particular application to its use with tapping attachments. While I have shown and described but a single embodiment of my invention, it is to be understood that it is capable of many modifications. Changes, therefore, in the construction and arrangement may be made which do not depart from the spirit and scope of the invention as disclosed in the appended claims.

I claim:

1. In a tapping machine, a shaft, means for rotating the shaft, an operating rod movable up and down, means operably connecting said rod and the shaft for raising and lowering the shaft including two springs, one of which is yieldable as the rod is raised and the other is yieldable as the rod is lowered, and a sleeve enclosing each of the springs, both sleeves being individually adjustable by an operator from his normal position while operating the machine.

2. In a tapping machine, a shaft, means for rotating the shaft, an operating rod movable up and down. means operably connecting said rod and the shaft for raising and lowering the shaft including two springs, one of which is yieldable as the rod is raised and the other is yieldable as the rod is lowered, and a sleeve enclosing each of the springs, the rod and the two springs being in alignment, both sleeves being individually adjustable by an operator from his normal position while operating the machine.

3. In a tapping machine, a shaft, means for rotating the shaft, an operating rod movable up and down, means operably connecting said rod and the shaft for raising and lowering the shaft including two springs, one of which is yieldable as the rod is raised and the other is yieldable as the rod is lowered, a sleeve enclosing each of the springs, and means operable by each sleeve for adjusting the stress in its spring.

. (l. In a tapping machine, a shaft, means for rotating the shaft, an operating rod movable up and down, means operably connecting said rod and the shaft for raising and lowering the shaft including two springs, one of which is yieldable as the rod is raised and the other is yieldable as the rod is lowered, a sleeve enclosing each of the springs, and means operable by each sleeve for adjusting the stress in its spring, the two sleeves being in axial alignment.

5. In a tapping machine, a shaft, means for rotating the shaft, an operating rod movable up and down, means operably connecting said rod and the shaft for raising and lowering the shaft including two springs, one of which is yieldable as the rod is raised and the other is yieldable as the rod is lowered, a sleeve enclosing each of the springs, and means operable by each sleeve for adjusting the stress in its spring,the two sleeves being in axial alignment and being connected so that either can be rotated with respect to the other to individually adjust either spring.

HARRY G. PROCUNIER. 

